Um, turbo's don't use pulley's. :-)
Anyhow, one must first size the unit correctly, turbocharger
or supercharger. Pull one of the classic big Detroit blowers
off a diesel and mount it on an automotive engine, and yes
you'll have wild boost at 3,000 rpms. That's why you'd need
a small unit for a small engine, and a tiny unit for a Spitfire.
Variable pulley size is one way to deal with overboost on a
supercharger. As are pressure relief valves, variable vane
geometry (Paxton) and such.
But when it's all said and done, Joe said it well. After spending
lots of money and blood on a Spitfire engine, you'll still have a
fragile Spitfire engine that will not match a modern engine
(or drive train) in any way shape or form. Which leaves one
to decide which direction they wish to go.
>>> Craig Smith <CraigS@iewc.com> 01/04 1:51 PM >>>
What about reducing supercharger speed via a pulley reduction or
enlargement.
A full wide open charge would eventually blow up the works.
Joe is correct. I had a Corvair Turbo that we changed the pulley size to
increase blower pressure.
Ran like a scalded dog for about 1,000 miles.
Way fun.
But it eventually blew a head gasket on the way to eating all the valves via
the top of the piston.
I really believe we could have driven that car as it was from the factory
over a 100,000 miles if we hadn't played around with the pressure.
I didn't check to see if the Shorrocks had a safety blow out or not.
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